RC Drill Bits

RC Drill Bits for 3–10 Inch Reverse Circulation Hammer Systems

An RC drill bit, also called a reverse circulation drill bit or RC drilling bit, is designed to work with an RC hammer and help direct newly produced rock cuttings into an internal sample-return passage.

MSD supplies RC drill bits for 3, 4, 5, 5.5, 6, 8, and 10 inch RC hammer systems. The current parameter tables include 12 confirmed Bit Shank configurations—RE531, RE004, RE542, RE543, RE545, PR40, PR52, RE547, PR54, RC6A, RC8A, and RC10A—with listed bit diameters from 85 to 360 mm.

The complete parameter row should be checked before ordering. A nominal hammer-system size does not mean that every diameter, button layout, face option, shroud diameter, or weight is available for every Bit Shank.

RC Bit Configuration Differences

The 3 and 4 inch ranges each use a confirmed RE-series Bit Shank. Their listed diameters, button layouts, shroud diameters, and weights differ.

The 5 and 5.5 inch ranges contain multiple RE- and PR-series Bit Shanks. Two RC drill bits within the same nominal hammer-system size may use different shanks and therefore match different RC hammer configurations.

The 6, 8, and 10 inch hammer-system ranges currently list RC6A, RC8A, and RC10A bit configurations. These configurations must be checked against the exact RC hammer model and confirmed Bit Shank designation rather than selected only by finished-hole diameter.

Shroud diameter and weight also vary by individual parameter row. These values should be reviewed together with the Bit Shank, bit diameter, button layout, and matched hammer, especially for larger RC bit configurations.

How RC Drill Bits Support the Sample-Return Path

In a conventional DTH drilling system, cuttings normally return through the annular space between the drill string and the borehole wall. A reverse circulation drilling system uses a different return pathway.

In a typical RC system, the RC bit breaks the formation and helps direct rock cuttings into the center return path. The cuttings then travel through the internal passage and the inner tube of the dual-wall drill pipe before reaching the surface collection system.

This internal return arrangement helps separate freshly produced sample material from the borehole wall after it leaves the bit face. It does not guarantee uncontaminated samples under every condition. Actual sample quality also depends on the RC hammer, dual-wall drill pipe, connection sealing, compressor capacity, formation, groundwater conditions, drilling procedure, and surface sampling equipment.

Matching the RC Bit With the RC Hammer

An RC drill bit cannot be selected independently from the RC hammer. The Bit Shank must match the exact hammer configuration, while the selected diameter must remain within the confirmed working range of the matched hammer.

The current product range includes:

• RE-series Bit Shanks: RE531, RE004, RE542, RE543, RE545, and RE547

• PR-series Bit Shanks: PR40, PR52, and PR54

• RC-series Bit Shanks: RC6A, RC8A, and RC10A

For replacement orders, the existing RC hammer model and confirmed Bit Shank designation should take priority over the general size description. A drawing, previous order record, or clear photograph of the current bit and hammer connection can help confirm the required reverse circulation hammer bit.

The complete RC drilling system should also be reviewed against the dual-wall drill pipe, rig, rotation head, compressor capacity, drilling depth, formation, and sample-return requirements.

Face and Button Layout Options

The parameter tables list gauge-button layouts and front-button layouts for flat and concave face options. Gauge Buttons describe the outer cutting-button arrangement and should not be treated as a face configuration.

Convex-face data is listed only for RC10A. It should not be assumed that every RC drill bit size or Bit Shank is available with flat, concave, and convex face options.

The required button and face layout should be reviewed according to the confirmed parameter row, matched RC hammer, required diameter, and drilling formation. No single layout should be presented as suitable for every working condition.

Typical RC Drilling Applications

RC drill bits are primarily used in projects that require returned rock-chip samples for geological or operational evaluation.

• Mineral exploration

• Resource-definition drilling

• In-pit grade control

• Geological sampling

• Selected geotechnical investigation

RC drilling may be appropriate where continuous chip-sample recovery is required but full core recovery is not the project objective. Suitability still depends on the formation, hole requirements, drilling depth, rig configuration, and sampling program.

Information to Confirm Before Ordering

To confirm a suitable RC drill bit, provide:

RC Hammer Model — Exact hammer model currently used or proposed.

Bit Shank — Required RE-, PR-, or RC-series shank designation.

Required Diameter — Finished bit or hole diameter in millimeters or inches.

Button Layout — Current or required gauge-button and front-button configuration.

Face Configuration — Required flat, concave, or confirmed convex configuration where listed.

Drilling Conditions — Formation hardness, abrasiveness, groundwater conditions, expected depth, and known wear problems.

RC System Information — Rig model, dual-wall drill pipe, compressor capacity, and sample-return arrangement.

Current Product Details — Existing bit markings, dimensions, drawings, photographs, or previous order information.

Order Requirement — Required quantity.

For replacement orders, the confirmed hammer model, Bit Shank, current bit dimensions, and existing product details should take priority over a general request such as “5 inch RC bit.”

RC Drill Bit Manufacturer and Supplier

MSD is a China-based RC drill bit manufacturer and supplier providing reverse circulation drill bits, matching RC hammers, and related rock-drilling tools.

The MSD team reviews each requirement according to the complete RC drilling system rather than only the requested bit diameter. Important factors include the hammer model, Bit Shank, button layout, face configuration, shroud diameter, formation, drilling depth, compressor capacity, and sampling requirements.

This review helps reduce the risk of ordering an RC drill bit that does not match the existing hammer or drilling conditions.

Technical content reviewed by MSD Engineering Team. | MSD — 23+ years of rock drilling tools manufacturing expertise | ISO 9001 Certified | Exporting to 40+ countries